In light of increasing climate change, a shift from fossil fuels to renewable energies is urgently needed. With wind energy as the most important sustainable energy source in Germany, the state of Rhineland-Palatinate has committed to an annual expansion of 500 megawatts. Here, we use an interactive map to show the current state of wind energy in this federal state to assess future expansions with regard to aspects of sustainability. More sites show to be suitable due to favorable wind exposure, minimum distances from dwellings, and separation from conservation areas. Nevertheless, regional planning often proves difficult due to arguments of bird protection, landscape aesthetics, as well as noise pollution and shading of neighboring residential areas. A common path is needed to contest the shift away from fossil fuels and harness the wind of change.
The extreme weather events are some of the most observable results of climate change, caused by the exacerbated use of fossil fuels in the last century. International agreements work synergically to reduce the greenhouse gas emissions registered in 2010 by 45% until 2030 to mitigate these effects (United Nations, 2022). One of the most promising ways to reach this target goal is by using renewable energy sources. Wind energy is currently the most important source of energy for Germany, accounting for 27 % of electricity generation in 2020 (Fraunhofer ISE, 2021).
To reach the international target goal, the Erneuerbare-Energien-Gesetz (EEG, engl. Renewable Energy Sources Act) in Germany had originally stated a goal of producing 71 gigawatts (GW) by 2030, but last year the new Minister of Economy Robert Habeck stated that 2% of the country’s land must be covered with wind energy turbines to reach a much-needed goal of 100 GW. This would mean an increase of 4 to 7 GW per year (Umweltbundesamt, 2021). Currently, there are over 28,000 onshore turbines with a total capacity of around 56 GW. In 2021, 484 new wind turbines with a total capacity of almost 2 GW were erected. Rhineland-Palatinate (RLP) installed 16 of these turbines (Deutsche WindGuard, 2021).
The recent and planned changes in wind energy policies in the federal state display compromise for improvement. The current coalition agreement established a net expansion of 500 megawatts (MW) of wind power per year (Koalitionsvertrag Rheinland-Pfalz, 2021). Smart infrastructures will be designed to provide a balance in the event of fluctuations in production or consumption through better distribution and storage of energy to further develop the energy source (Henning & Palzer, 2012). By the end of the decade, the goal is to generate all the electricity consumed from renewable energies and afterward pursue to export the surplus of energy (Koalitionsvertrag Rheinland-Pfalz, 2021). Several big changes are being implemented to reach the goals, including a) proposed changes in construction permits depending on the height of the turbine, b) solidarity pact for municipalities, and c) centralization, standardization, and simplification of approval procedures at the Struktur und Genehmigungsdirektionen (SGDs; Fachagentur Windenergie an Land, 2021; Ministerium des Innern und für Sport Rheinland-Pfalz, 2022).
Nonetheless, many aspects must be controlled to allow the erection of wind energy plants in RLP, including urban land use planning, building regulations, immission control, nature conservation law, and administrative procedures (Ministerium für Wirtschaft Klimaschutz Energie und Landesplanung Rheinland-Pfalz et al., 2013). The third partial update of the Landesentwicklungsprogramm IV (engl. State Development Program IV) has set the specific goal of 2% of the federal state’s land area to be set aside for wind energy use. It has also made changes that allowed for some areas, like forest areas with high wind potential, to be designated and prioritized for wind energy use. This prioritization could exclude certain areas from the wind energy planning, such as nature parks, national parks, and the identified core zones of UNESCO World Heritage Sites (Ministerium für Wirtschaft, Klimaschutz, Energie und Landesplanung Rheinland-Pfalz, 2013; Ministerium des Innern und für Sport Rheinland-Pfalz, 2022). Additionally, areas of high concern due to immission, and drinking water protection must be studied before the approval can be granted (Fachagentur Windenergie an Land, 2021). According to changes proposed in the coalition agreement, the distance of new turbines from residential areas is at least 900 m. For the re-powering of turbines, the minimum distances can be reduced 20% and more focus will be given to higher output rather than number of wind turbines. The assessment of the minimum building distances will be carried out from the center of the mast base of the wind turbine so the space can be optimized, and the goals can be reached. Even in forests, wind turbines will be installed in areas of mixed hardwood older than 100 years and a stand area of more than 10 hectares should be excluded (Koalitionsvertrag Rheinland-Pfalz, 2021).
Despite these changes in state policies, it is still argued that the issue of sufficient provision of usable area has not been resolved (Umweltbundesamt, 2021). This leads to the question of whether the federal state will be able to reach the 500 MW yearly goal they have set and if this is viable within the pillars of sustainability. To answer this question this paper shows the current location of wind turbines and wind speed data, to show the areas where there is a good exposure to natural wind currents to effectively harvest energy. The paper strives to initiate a discussion about the further potential in the state and whether the goals proposed by RLP are achievable.
To explore the current state of wind energy in RLP an interactive map was set up in R version 4.1.1 (R Core Team, 2021) using the leafletR package (Graul, 2016). Regarding the coordinate reference system, WGS84 with EPSG4326 was adopted for all layers. OpenStreetMap® was chosen as the default base map as it depicts most detailed the local infrastructure in the selected region. Optionally, switching to OpenTopoMap® provides information on the topography as an important factor for the occurrence of wind currents as well as wind speed and therefore also the evaluation of suitable turbine sites. As a fixed element, the county border of RLP was integrated using rgdal package (Bivand et al., 2021) in form of a shape file, which is available for free use from Esri Deutschland (2019) and marks the area of interest for this project.
Two overlays were added from the Global Wind Atlas as tif-files, a service owned and operated by the Technical University of Denmark (2019). With a resolution of 250 meters, they visualize the mean annual wind speed [m/s] measured 100 and 150 meters above the ground for the period from 2008 to 2017. Thereby, the layer depicting the wind speed in 100 meter height reflects best the conditions for currently operating turbines with an average hub height of 112.1 meter, while the wind speed in 150 meter height helps evaluating the wind conditions for planned turbines with an average hub height of 148.5 meters. Overall, the layers serve as an indication where suitable wind speeds are available as a prerequisite for the cost-effective operation of wind turbines. In addition, open source data on wind park locations and wind turbine characteristics was retrieved from Marktstammdatenregister of the Bundesnetzagentur für Elektrizität, Gas, Telekommunikation, Post und Eisenbahnen (2020; engl. Federal Network Agency for Electricity, Gas, Telecommunications, Post and Railway). This is an official register where market players in the energy sector must register themselves and the master data of their installations (e.g. location details, technical data for installations). More specifically, all players who perform a function on the energy market are obligated to register, as are all generation facilities that are connected to the high-voltage grid in the case of electricity or to the transmission grid in the case of gas. Excluded were 14 cases whose geographical data were incomplete and 41 cases that were registered by companies in RLP but where the turbines were not located within the state’s borders. Custom-made turbine icons were integrated with addLegendImage() function from the leaflegend package (Roh & Rodrigo Basa, 2022) to mark the wind turbine location, with different colors reflecting the current operational status (i.e., if they are in operation, planned or shut down). Through the usage of popupTable function from the leafpop package (Appelhans & Detsch, 2021), one is able to retrieve further information on the characteristics of the wind turbine by clicking on the respective icon.
For RLP, a total of 1810 wind turbines are indicated by the Bundesnetzagentur (2020), including 21 shut down, 84 planned and 1705 currently operating turbines. Graphical inspection reveals that the state has many areas with average wind speeds between 2 to 6 m/s and little that is above 6 m/s in 100 meter height. Compared with the north and northwest of Germany, therefore, the picture is rather mixed with regard to the natural conditions for the production of wind energy. Due to their topography, areas around the low mountain ranges of Hunsrück and Eifel depict the highest average wind speeds in the federal state. Thus, the target of minimal wind speeds necessary for the operation of turbines is met, but optimal speeds with more than 9 m/s are rare with the currently average hub height of 112.1 meter. Over time, both turbine outputs and hub heights have increased, and so the average hub height of planned turbines is with 148.5 m approximately 32% higher than those currently operating. By activating the overlayer with wind speeds in 150 meter height more areas display suitable natural conditions for future turbine installations.
Technically it has to be noted that when both wind maps are selected, only the one in 150 meter height will be displayed as it is the last one called in R. However, the leaflet function addLayersControl is not enabling overlay groups in a single choice format. The alternative option of inserting the wind maps as base groups would have posed further problems: (1) the entire world map was not freely available and thus (2) only Germany with a white world map around could have been displayed. Additionally, sometimes the Open Street Map indicates turbines where the data provided by the Bundesnetzagentur (2020) does not list any installations. One possibility is that these are consumer installations that are not subject to registration because they are not connected to the high-voltage grid and do not serve to supply third parties. Another explanation could be a potential data gap or error, but the usage of data from the Bundesnetzagentur (2020) is the best approximation of the current state of wind energy through the registration obligation of power generation units in Germany.